Study Of Semi-Active Suspension System Based On Stability Mechanism And Vibration Characteristic Of High-Speed Train

The semi-active suspension system is effective method for isolating the carbody vibration and improving the ride performance. The development of the high-speed train technology promote the running speed to reach a higher range. The operating condition has great changes in this range, the increases of Track excitation frequency, the wheel wear intensifies, and the vehicle stability highlighted.These changes have brought a new challenge for the application of the semi-active suspension technology in the high-speed trains.Therefore, it is significant to carry out the research of semi-active suspension technology appled in the high speed train. An indenstiy reaserch of semi-active suspension is carried out in this thesis. The main researeh works of the thesis are as below:1)3DOFs (degrees of freedom) vehicle systems model, and50DOF vehicle systems model is set up respectively. The longitudinal, lateral and vertical movement are coupled in the50DOF vehicle systems model. And the nonlinear characteristics of the suspension and wheel-rail are considered in the model.2) The semi-active suspension system model is established, compresed of semi-active controller model, sensor model and semi-active damper model. The operating principle of semi-active damper with proportional relief valve is analyzed and modeled. Accrording to the test data, a viscoelastic plastic continuous physical model of the MR (magnetorheological) damper is proposed. The parameters solution method is given. The revese model of the MR damper is set up by using the method of separating the hysteresis function.3) Using the model of high-speed trains and semi-active suspension system model, the stability of high-speed train equipted with the semi-active suspension is studied. Based on the nonlinear vibration bifurcation theory and the Poincare mapping, the bifurcation of high-speed train with the high and low equivalent concity thread is calculated. And then the interaction of semi-active suspension system and the hunting motion is analyzed. The difference between the passive suspension vehicle and semi-active vehicle is shown and explained from the viewpoint of energy theroy. 4) The isolation vibration characteristic of semi-active method is studied by using the1DOF and2DOF vibration systems. And then perfomence of semi-active suspension system with the the proportional relief valve type damper and the MR damper is investegted respectively. At last, the relationship between the performance of the semi-active suspension system and the operation condition, including the type of vehicle, running speed and the track excitation is analyzed.5) A new semi-active suspension system solutions applied in the high-speed trains is proposed, it is composed of stability controller, comfort controller and train crossing vibration controller. The new semi-active suspension system can improve effectively the stability of vehicle quipted with the low concity thread in the wear stated, and shock the vibration produced by the train crossing pressure.6) Based on the research result of the stability of semi-active high-speed trains and the isolation vibration performance of semi-active suspension, the hunting instability and the low frequency vibration of carbody is analyzed. The solution based on the new semi-active suspension is appled in the solution of those problems.